This invention pertains to four wheeled vehicles built around a moped, motor bike or the like two wheeled vehicle. In known vehicles of this type, either the stabilizing wheels are retractable when the vehicle is moving or are intended only to assure its stability when it is stopped. If they keep their contact with the ground during maneuvers of the handlebars, this disturbs the natural conditions of dynamic equilibrium of the vehicle since nothing is provided to take into account clearances of the stabilizing wheels by irregularities of the ground of one or other or both in a straight line or during turning.